This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
The Effects of Orifice Shape on Diesel Combustion
Technical Paper
2004-01-2920
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Combustion and emission formation in a diesel engine are governed by fuel spray formation and mixing processes. Spray formation depends mainly on the fuel injection system and its use, i.e. injection strategies. Since future emission legislation will focus on sharply reducing emissions such as NOX and particulate, spray formation and consequently the fuel injection system take on increasing importance. Over the years, the adoption of electronically controlled fuel injection systems and higher fuel injection pressure have led to a decrease in fuel consumption, and compliance with emission legislation has been achieved. To achieve higher injection pressures, much energy needs to be provided from the engine, i.e. parasitic losses increase. Developments in manufacturing techniques now make different shapes of the orifices on the fuel injector nozzle possible. This includes very small orifice diameters, high inlet corner rounding and, more recently, conically shaped orifices beside several rows of orifices on the nozzle. A differently shaped orifice could lead to lower emissions at the same injection pressure level, i.e. emission reduction without an increase in the parasitic losses. This would then enable a better trade-off between fuel consumption and emissions.
This paper investigates the effects on emissions and fuel consumption of five nozzles with different orifice shapes by using a heavy-duty single-cylinder engine under the same injection pressure conditions. To further try to distinguish the effects of the orifice shapes, the minimum orifice diameter was kept constant. The results show that orifice shapes resulting in lower fuel flow rates can yield lower fuel consumption and lower emissions than orifice shapes that have larger fuel flow rates. A negative conisity (divergent) orifice shape yields lower emissions and has lower fuel consumption than the reference nozzle with a cylindrical orifice shape. It is also shown that in terms of fuel consumption, a 50% HE grinded orifice is a more beneficial selection than a positive conisity orifice shape.
Recommended Content
Authors
Citation
Bergstrand, P., "The Effects of Orifice Shape on Diesel Combustion," SAE Technical Paper 2004-01-2920, 2004, https://doi.org/10.4271/2004-01-2920.Also In
References
- Chomiak, J. Karlsson, A. “Flame liftoff in Diesel Sprays” Twenty-Sixth Symposium on Combustion/The Combustion Institute 2557 2564 1996
- Siebers, D. L. Higgins, B. S. “Effects of Injector Conditions on the Flame Lift-Off Length of DI Diesel Spray” Thiesel 2000
- Bergstrand, P. Försth, M. Denbratt, I. “The Influence of Orifice Diameter on Flame Lift-off Length” ILASS-Europe Zaragoza 2002
- Bergstrand, P. Persson, F. Försth, M. Denbratt, I. “A Study of the Influence of Nozzle Orifice Geometries on Fuel Evaporation using Laser-Induced Exciplex Fluorescence” JSAE paper 20030217 SAE paper 2003-01-1836 2003
- Bergstrand, P. Denbratt, I. “Diesel Combustion with Reduced Nozzle Orifice Diameter” SAE Paper 2001-01-2010 2001
- Bergstrand, P. Denbratt, I. “The Effects of Leaner Charge and Swirl on Diesel Combustion” SAE Paper 2002-01-1633 2002
- Bergstrand, P. Denbratt, I. “The Effects of Multirow Nozzles on Diesel Combustion” SAE Paper 2003-01-0701 2003
- Yoda, T. Tsuda, T. “Influence of Injection Nozzle Improvement on DI Diesel Engine” SAE Paper 970356 1997
- Bergstrand, P. Small Orifices - Diesel Combustion and Spray Investigations 91-7291-312-6 2003
- Schmid, M. Leipertz, A. Fettes, C. “Influence of Nozzle Hole Geometry, Rail Pressure and Pre-Injection on Injection, Vaporisation and Combustion in a Single-Cylinder Transparent Passenger Car Common Rail Engine” SAE Paper 2002-01-2665 2002
- Bergstrand, P. Försth, M. Denbratt, I. “Investigation of Diesel Spray Injection into High Pressure Conditions with Reduced Nozzle Orifice Diameter” JSAE Paper 20015324 2001
- Heywood, J., B. Internal Combustion Engine Fundamentals Mc Graw-Hill, Inc. 1988
- Dec, J. “A Conceptual Model of DI Diesel Combustion Based on Laser-Sheet Imaging” SAE Paper 970873 1997
- Schugger, C. Renz, U. “Experimental Investigation of the Primary Breakup Zone of High Pressure Diesel Sprays from Multi-Orifice Nozzles” ICLASS 2003
- Kampmann, S. Dittus, B. Mattes, P. Kirner, M. “The Influence of Hydro Grinding at VCO Nozzles on the Mixture Preparation in a DI Diesel Engine” SAE Paper 960867 1996